Tool-holder.



J. ARMSTRONG.

00L HOLDER.

AEPL N FILED JAN. 1.4.. 1916.

1 ,QllQfiQ? I Patented Feb. 6, 1917.

JAMES ARMSTRONG, 0F CHTGAGO, ILLINOIS, ASSIGNOR T0 ARMSTRONG BTHERS TOOL COMPANY, OE CHICAGQ, ILLINOIS, A CORPORATION OF ILLINOIS.

TOOL-HOLDER.

Specification of Letters Patent.

Patented Feb. 8, 1913..

Application filed January 14, 1916. Serial Ito. 7%,017.

To all whom it may concern:

Be it known that 1, JAMES ARMSTRONG, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful lm rovements in Tool-Holders, of which the fol owing is a specification.

This invention relates to tool holders for lathes or other metal working machines. As usually constructed, the tool clamping means of such tool holders bears directly upon a relatively small part of the tool held. For example, if the clamping means be a cam bearing directly on the tool, its bearing surface on the tool would be represented by a thin line dra wn across the face of the tool; and tools made from stellite or material of a similar brittle nature are very likely o break along this thin line of clamping surface under the shock and strain of operation.

It is one of the objects of my invention to eliminate the breakage of tools made from stellite, etc., and this object is accomplished by. providing an intermediary ,member between the clamping means and the tool, which member has a large face adapted to bear against the tool so that the pressure of the clamping means will be distributed over a considerable area on the tool.

Another object of the invention relates to the means for supporting this intermediary member in the absence of the tool and in such a manner as to permit the necessary play of said member in performing its function.

A further object is to provide a spacer device to limit the movement of the clamping screw so that in the absence of the tool said screw cannot be turned down so far as to shear oflor otherwise damage the support for the intermediary member.

In the accompanying drawings, Figure 1 is a side elevation of a tool-holder embodying the features of my'invention. Fig. 2 is a longitudinal central section in the plane of line 22 of Fig. 3. Fig. 3 is a front elevation with the tool shown in section. Fig. 4 is a transverse section in the plane of line 44 of Fig. 1. Fig. 5 represents a side elevation and a plan view of the intermediary member which engages the tool.

My invention is susceptible of embodiment in various forms, only one of which is illustrated in the drawing and will be set forth in the following description. Therefore no limitation of the invention is to be understood from this disclosure, the scope of the invention being pointed out in the appended claims.

The tool holder comprises a suitable body having the usual inclined socket 11 to receive the tool 12. The tool-clamping means herein shown comprises a set-screw 13 which is threaded into the top of the body and a member H which is positioned between the lnner end of the screw and the tool and which has a large flat face at its lower side adapted .to bear directly against the tool. This member acts as an intermediary to receive the pressure from the clamping means 13 and distribute such pressure over a large area on the tool. The result is that breakage ofthe tool is practically, eliminated. The member also provides a better grip on the tool to obviate all tendency to chattering.

The member 14 fits loosely in a recess 15 which is located at the upper side of and merges into the tool socket 11. Said memberis loosely supported in a manner to allow the necessary play of the member in performing its function. The supporting means preferably comprises a screw 16 passing loosely through a transverse hole 17 in the member and threaded into the body. If desired, the member 14 may also have on its rear end a projection 18 to occupy a depression 19 in the end of the recess.

It is desirable to provide means to prevent the screw 16 from being sheared ofi' or damaged in the absence of the tool by turning the set screw 13 down too far. Such means is herein shown as comprising a spacer or collar 20 surrounding the reduced portion or neck of the set screw just below the head thereof. 'ThiS collar isinternally threaded so that it may be turned onto the set screw before the latter is mounted in the holder. The parts are so proportioned that when the tool 12 is absent from the holder the turning down of the set screw will carry the head thereof into abutment with the collar 20 to stop the screw before it causes damage to the screw 16 by pressure on the member 14. After the tool holder has been in use some time, if the tip of the screw 13 or the-member 14 becomes worn to such an extent that the collar 20 prevents the screw 13 from exerting the proper clamping action on the tool, the collar may be ground down to reduce its thickness, or a thinner 4 collar may be substituted therefor.

I claim as my invention:

1. A tool-holder comprising a body having a tool-receiving socket and having a recess merging into said socket, a member movably fitting into said recess and having a large face arranged to bear against the tool, said member having a transverse opening therethrough, a screw passing loosely through said opening and seated in the body to support said member in the absence of the tool, a screw threaded in the body and bearing at one end against said member to clamp the latter against the tool, and a spacer beneath the head-of the latter screw to limit the movement thereof and prevent damage to the first mentioned screw.

2. A tool-holder comprising a body, a member having a large face to bear against the tool, a. screw threaded in the body and adapted to engage said member to clamp the latter against the tool, means for supporting said member in the absence of the tool, and a spacer under the head of said screw to limit movement thereof and prevent damage to said supporting means.

3. A tool-holder comprising a body hav ing a tool-receiying socket and having a recess merging into sald socket, a member movably fitting in said recess and having a. large face arranged to bear against the tool, one end of said member having a projection arranged to engage in a depression in the end wall of said recess to partially support said member, said member having a transverse hole therethrough, a screw passing loosely through said hole and seated in the body for supporting said member, and means for clamping said member against the tool. I

4. A tool-holder comprising a body having a tool-receiving socket and having a recess merging into said! socket, a member movably fitting in said recess and having a large face arranged to bear against the tool, one end of 'saidmember being arranged to engage the wall of said recess to partially support said member. a screw seated in the body and arranged to loosely engage in an openlng in said member to support the latter, and means for clamping said member against the tool.

In testimony whereof, I hereunto set my hand.

' JAMES ARMSTRONG.

In the presence of- W. J. BRADDOOK, C. A. RANDALL. 

